# Fix RGB Range Limit on MacOS

> Source: <https://gist.github.com/FelikZ/e287c60e0407f9eeb5434471ad050ff9>
> Published: 2025-10-14 17:54:03+00:00

rgb-fix.sh

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#!/usr/bin/env bash

# Script to force RGB Color Output on M1 and M2 based Macs for a selected display

# Function to display an error message and exit

function error_exit {

    echo "Error: $1" >&2

    exit 1

}

# Function to check if a command executed successfully

function check_success {

    if [ $? -ne 0 ]; then

        error_exit "Command failed: $1"

    fi

}

set -e

ORIGINAL_PLIST="/Library/Preferences/com.apple.windowserver.displays.plist"

TEMP_DIR="$HOME/Downloads"

TEMP_PLIST="$TEMP_DIR/com.apple.windowserver.displays.plist"

# Step 1: Unlock the file if locked

sudo chflags nouchg "$ORIGINAL_PLIST" || true

echo "Step 1: File unlocked if necessary."

# Step 2: Copy the plist to temp directory

sudo cp "$ORIGINAL_PLIST" "$TEMP_PLIST"

sudo chown "$USER" "$TEMP_PLIST"

check_success "Copying the plist file"

echo "Step 2: File copied successfully."

set +e

# List displays from plist, matched with system_profiler names by resolution

num=$(python3 -c "

import plistlib, subprocess, json, sys

file = '$TEMP_PLIST'

with open(file, 'rb') as f:

    data = plistlib.load(f)

displays = data['DisplayAnyUserSets']['Configs'][0]['DisplayConfig']

sp_json = json.loads(subprocess.check_output(

    ['system_profiler', 'SPDisplaysDataType', '-json'],

    stderr=subprocess.DEVNULL

))

sp_displays = []

for gpu in sp_json.get('SPDisplaysDataType', []):

    sp_displays.extend(gpu.get('spdisplays_ndrvs', []))

name_by_res = {}

for d in sp_displays:

    pixels = d.get('_spdisplays_pixels', '')

    name = d.get('_name', '')

    if pixels and name:

        name_by_res[pixels.replace(' ', '')] = name

print(len(displays))

print('Connected displays:', file=sys.stderr)

for idx, disp in enumerate(displays):

    info = disp.get('CurrentInfo', disp.get('UnmirrorInfo', {}))

    w = info.get('Wide', 0)

    h = info.get('High', 0)

    scale = info.get('Scale', 1)

    hz = info.get('Hz', 0)

    pw, ph = int(w * scale), int(h * scale)

    name = name_by_res.get(f'{pw}x{ph}', f'Display {idx}')

    print(f'{idx + 1}: {name} ({pw}x{ph} @ {hz}Hz)', file=sys.stderr)

")

if [ -z "$num" ] || [ "$num" -eq 0 ]; then

    error_exit "Unable to parse number of displays from plist."

fi

# Ask user to choose

read -p "Enter the number of the display to update (1-${num}): " choice

if ! [[ "$choice" =~ ^[0-9]+$ ]] || [ "$choice" -lt 1 ] || [ "$choice" -gt "$num" ]; then

    error_exit "Invalid choice."

fi

i=$((choice - 1))

# Get the UUID of the selected display

uuid=$(python3 -c "

import plistlib

with open('$TEMP_PLIST', 'rb') as f:

    data = plistlib.load(f)

    print(data['DisplayAnyUserSets']['Configs'][0]['DisplayConfig'][$i]['UUID'])

" 2>/dev/null)

if [ -z "$uuid" ]; then

    error_exit "Unable to retrieve UUID for the selected display."

fi

echo "Modifying ${uuid}..."

# Ask user for bit depth

read -p "Enter the bit depth (8 or 10): " bit_depth_choice

if ! [[ "$bit_depth_choice" == "8" || "$bit_depth_choice" == "10" ]]; then

    error_exit "Invalid bit depth. Please enter 8 or 10."

fi

# Step 4: Modify the plist using embedded Python with plistlib

python3 -c "

import plistlib, sys

file = '$TEMP_PLIST'

uuid = '$uuid'

bit_depth = int('$bit_depth_choice')

link_desc = {

    'BitDepth': bit_depth,

    'EOTF': 0,

    'PixelEncoding': 0,  # 0 = RGB

    'Range': 1           # 1 = Full Range

}

with open(file, 'rb') as f:

    data = plistlib.load(f)

modified_count = 0

# Modify DisplayAnyUserSets section

if 'DisplayAnyUserSets' in data and 'Configs' in data['DisplayAnyUserSets']:

    for config in data['DisplayAnyUserSets']['Configs']:

        if 'DisplayConfig' in config:

            for disp in config['DisplayConfig']:

                if 'UUID' in disp and disp['UUID'] == uuid:

                    disp['LinkDescription'] = link_desc.copy()

                    modified_count += 1

# Modify DisplaySets section (CRITICAL - was missing before!)

if 'DisplaySets' in data and 'Configs' in data['DisplaySets']:

    for config in data['DisplaySets']['Configs']:

        if 'DisplayConfig' in config:

            for disp in config['DisplayConfig']:

                if 'UUID' in disp and disp['UUID'] == uuid:

                    disp['LinkDescription'] = link_desc.copy()

                    modified_count += 1

print(f'Modified {modified_count} display config entries for UUID {uuid}')

with open(file, 'wb') as f:

    plistlib.dump(data, f, fmt=plistlib.FMT_BINARY)

"

check_success "Modifying plist with Python"

echo "Step 4: Plist modified successfully."

# Step 5: No conversion needed since edited in binary

# Step 6: Validate the plist

plutil -lint "$TEMP_PLIST"

check_success "Validating plist"

echo "Step 6: Plist validated successfully."

# Step 7: Backup original file (only if backup doesn't exist, to preserve original)

if [ ! -f "${ORIGINAL_PLIST}_backup" ]; then

    sudo cp "$ORIGINAL_PLIST" "${ORIGINAL_PLIST}_backup"

    check_success "Backing up original file"

    echo "Step 7: Original file backed up successfully."

else

    echo "Step 7: Backup already exists, skipping (preserving original backup)."

fi

# Step 8: Remove user preferences if exists (they can override system settings)

if [ -f "$HOME/Library/Preferences/com.apple.windowserver.displays.plist" ]; then

    if [ ! -f "$HOME/Library/Preferences/com.apple.windowserver.displays.plist_backup" ]; then

        mv "$HOME/Library/Preferences/com.apple.windowserver.displays.plist" "$HOME/Library/Preferences/com.apple.windowserver.displays.plist_backup"

        check_success "Backing up user preferences"

        echo "Step 8: User preferences backed up successfully."

    else

        rm "$HOME/Library/Preferences/com.apple.windowserver.displays.plist"

        echo "Step 8: User preferences removed (backup already exists)."

    fi

fi

# Step 9: Remove ByHost preferences if exists (they can override system settings)

for file in "$HOME/Library/Preferences/ByHost/com.apple.windowserver.displays."*.plist; do

    if [ -f "$file" ] && [[ "$file" != *_backup ]]; then

        if [ ! -f "${file}_backup" ]; then

            mv "$file" "${file}_backup"

            check_success "Backing up ByHost file"

            echo "Step 9: ByHost file backed up successfully."

        else

            rm "$file"

            echo "Step 9: ByHost file removed (backup already exists)."

        fi

    fi

done

# Step 10: Copy modified plist back

sudo chown "root" "$TEMP_PLIST"

sudo mv "$TEMP_PLIST" "$ORIGINAL_PLIST"

check_success "Copying modified plist back"

echo "Step 10: Modified file copied back successfully."

# Step 11: Set Stationery flag and lock the file (as per original gist)

# Set Stationery Pad flag BEFORE locking (using SetFile if available)

if command -v SetFile &>/dev/null; then

    sudo SetFile -a T "$ORIGINAL_PLIST" 2>/dev/null || true

fi

# Lock the file

sudo chflags uchg "$ORIGINAL_PLIST"

check_success "Locking the file"

echo "Step 11: File locked successfully."

# Step 12: Verify the changes were applied

echo ""

echo "=== Verification ==="

link_count=$(python3 -c "

import plistlib

with open('$ORIGINAL_PLIST', 'rb') as f:

    data = plistlib.load(f)

count = 0

for section in ['DisplayAnyUserSets', 'DisplaySets']:

    if section in data and 'Configs' in data[section]:

        for config in data[section]['Configs']:

            for disp in config.get('DisplayConfig', []):

                if disp.get('UUID') == '$uuid' and 'LinkDescription' in disp:

                    count += 1

                    print(f'{section}: BitDepth={disp[\"LinkDescription\"].get(\"BitDepth\")}, PixelEncoding={disp[\"LinkDescription\"].get(\"PixelEncoding\")}, Range={disp[\"LinkDescription\"].get(\"Range\")}')

print(f'Total entries modified: {count}')

")

echo "$link_count"

echo ""

# Step 13: Ask for reboot

read -p "Changes applied. Reboot required. Do you want to reboot now? (Y/N): " reboot_choice

case "$reboot_choice" in

y | Y) sudo shutdown -r now ;;

n | N) echo "Reboot canceled. Please reboot manually for changes to take effect." ;;

*) echo "Invalid choice. Reboot canceled. Please reboot manually." ;;

esac

verify.sh

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#!/usr/bin/env bash

set -e

ORIGINAL_PLIST="/Library/Preferences/com.apple.windowserver.displays.plist"

TEMP_DIR="$(mktemp -d)"

TEMP_PLIST="$TEMP_DIR/com.apple.windowserver.displays.plist"

trap 'rm -rf "$TEMP_DIR"' EXIT

sudo cp "$ORIGINAL_PLIST" "$TEMP_PLIST"

sudo chown "$USER" "$TEMP_PLIST"

python3 <<PYEOF

import plistlib, subprocess, json

file = '$TEMP_PLIST'

with open(file, 'rb') as f:

    data = plistlib.load(f)

sp_json = json.loads(subprocess.check_output(

    ['system_profiler', 'SPDisplaysDataType', '-json'],

    stderr=subprocess.DEVNULL

))

sp_displays = []

for gpu in sp_json.get('SPDisplaysDataType', []):

    sp_displays.extend(gpu.get('spdisplays_ndrvs', []))

name_by_res = {}

for d in sp_displays:

    pixels = d.get('_spdisplays_pixels', '')

    name = d.get('_name', '')

    if pixels and name:

        key = pixels.replace(' ', '')

        name_by_res[key] = name

pixel_encoding_map = {0: 'RGB', 1: 'YCbCr 4:2:2', 2: 'YCbCr 4:4:4'}

range_map = {0: 'Limited', 1: 'Full'}

eotf_map = {0: 'SDR', 1: 'HDR'}

for section in ['DisplayAnyUserSets', 'DisplaySets']:

    if section not in data or 'Configs' not in data[section]:

        continue

    configs = data[section]['Configs']

    if not configs:

        continue

    config = configs[0]

    displays = config.get('DisplayConfig', [])

    print(f'\n=== {section} ({len(displays)} display(s)) ===')

    for idx, disp in enumerate(displays):

        uuid = disp.get('UUID', 'N/A')

        link = disp.get('LinkDescription', {})

        info = disp.get('CurrentInfo', disp.get('UnmirrorInfo', {}))

        w = info.get('Wide', 0)

        h = info.get('High', 0)

        scale = info.get('Scale', 1)

        hz = info.get('Hz', 0)

        pixel_w = int(w * scale)

        pixel_h = int(h * scale)

        res_key = f'{pixel_w}x{pixel_h}'

        name = name_by_res.get(res_key, f'Display {idx}')

        print(f'\n  [{idx + 1}] {name} ({pixel_w}x{pixel_h} @ {hz}Hz)')

        print(f'      UUID:          {uuid}')

        if not link:

            print('      LinkDescription: (not set)')

            continue

        bit_depth = link.get('BitDepth', 'N/A')

        pixel_enc = link.get('PixelEncoding', 'N/A')

        rng = link.get('Range', 'N/A')

        eotf = link.get('EOTF', 'N/A')

        pixel_label = pixel_encoding_map.get(pixel_enc, str(pixel_enc))

        range_label = range_map.get(rng, str(rng))

        eotf_label = eotf_map.get(eotf, str(eotf))

        print(f'      BitDepth:      {bit_depth}')

        print(f'      PixelEncoding: {pixel_enc} ({pixel_label})')

        print(f'      Range:         {rng} ({range_label})')

        print(f'      EOTF:          {eotf} ({eotf_label})')

print()

PYEOF